Process for preparing inner sulfonium salts



United States Patent 3,184,477 PRQCESS FUR PREPARlNG ENNER SmFfiNlUh i SAlJl William Baird, .l'ohn Woolley Batty, and Alexander Paritiuson, Manchester, England, assignors to Imperial Chemical industries Limited, London, England, a corporation of Great Britain No Drawing. Filed Dec. 31, 1962, Ser. No. 2 l8,233 Claims priority, application Great Britain, Jan. 15, 1962, 1,355/62 12 Claims. (Cl. 260-327) This invention relates to the manufacture of sulphonium salts.

We have previously described a process for the preparation of fi-hydroxyalkyl :sulphonium salts whereby an organic sulphide is reacted with an alkylene oxide in the presence of an aqueous acid. We have now found that sulphonium salts may be advantageously prepared by reacting an organic sulphide with an alkylene oxide in the presence of an acid anhydride or an acid halide.

Thus according to the present invention we provide a process for the manufacture of sulphonium salts or sulphonium inner salts which comprises reacting an organic sulphide R -SR., with an alkylene :oxide and an acid anhydride or an acid halide where R and R are the group (CHR, -CHR OH), or straight or branched chain substituted or unsubstituted alkyl, or substituted or unsubstituted allrenyl containing from 23 carbon atoms, aryl, aralkyl, alicyclic or heterocyclic groups as hereinafter defined the same or difierent, and R and R are hydrogen or lower alkyl, the same or .difierent, the lower alkyl group containing from 1 to 3 carbon atoms.

The straight or branched chain alkyl groups from which R and R may be selected may contain up to 22 carbon atoms but it is preferred that they contain fnom l to 18 carbon atoms. By a substituted alkyl group we mean a straight or branched chain alkyl group which may contain up to 22 carbon atoms and contain as substituents for example hydroxyl, carboxyl, ether, ester, mercapto, thicether, keto, cyano, sulphonic acid or sulphuric ester groups.

By alkenyl groups containing 2-3 carbon atoms, we mean aliphatic hydrocarbon groups which contain one double bond for example vinyl, methylvinyl or allyl groups. By aryl groups we mean those groups which are derived from a member of the benzene or naphthalene series, for example phenyl or naphthyl groups. lBy aralkyl groups we mean alkyl groups which are themselves substituted by an aryl group for example the benzyl group. By alicyclic groups we mean groups which contain a non benzenoid cyclic carbon ring, for example the cyclohexyl group. By heterocyclic groups we mean groups which contain a closed ring system of atoms containing at least one atom of an element other than carbon, e.g., oxygen, sulphur, nitrogen, for example the pyridyl or quinolyl groups. Any of the aforementioned groups may contain as substituents for example hydroxyl, carboxyl, ether, ester, mercapto, thioether, keto, cyano, sulphonic acid or sulphuric ester groups The reaction may be carried out in the presence or absence of an inert diluent or solvent or it may be convenient to employ an excess of one of the reagents as a solvent. Particularly suitable inert diluents or solvents include for example, methyl chloroform, totrachlorethaue, carbon tetrachloride, perchlorethylene or tric-hlorofluoroethane.

The reaction may be carried out at a temperature between 50 C. and 50 C. and it is particularly preferred to carry out the reaction at temperatures between 5 C and l5 C.

Organic sulphides which are suitable in the present 3,184,477 Patented May 18, 1965 invention include, for example, dimethyl sulphide, me-thyL ethyl sulphide, dioctadecyl sulphide, (,B-hydroxy-ethyDsulphide, benzyl sulphide, methyl vinyl sulphide, 'b-is(,8-hydroxyethyl)sulphide, bis(Z-hydroxypropylsulphid-e), methyl phenyl sulphide and suitable alkylene oxides include for example, ethylene, propylene and butylene oxides.

Suitable acid anhydrides which may be used in the present invention include for example carbon dioxide, sulphur dioxide, sulphur trioxide, acetic anhydi'ide, propi onic anhydride, maleic anhydride and succinic anhydride. We, particularly prefer to use sulphur dioxide.

Suitable aoid halides include, rfior example, acetyl chloride, Propionyl chloride or acetyl bromide.

As an illustration of the use of an acid anhydride in the present process, when sulphur dioxide dor example is reacted with ethylene oxide and thiodiglycol at low temperatures, optionally in the presence of an inert diluent or solvent, a bis(/3-hyd-roxyct-hyl) p-sulphitoethyl sulphonium inner salt is obtained. This may be readily converted to a trisw-hydroxyethyl) sulphonium salt, for example the chloride, by treating with, for example, hydrochloric acid. Again, as a further example, when acetic anhydnide is reacted with ethylene oxide and thindiglycol at low temperatures, optionally in the presence of an inent diluent or solvent, a product is obtained which may be converted to tris-(fi-hydroxyethybsulphoniurn chloride by treatment with hydrochloric acid.

When an acid chloride, for example acetyl chloride, is used in the process of the present invention the resulting sulphonium salt may be isolated as the chloride.

The products of the present invention are of industrial interest, for example as intermediates for textile auxi1 iaries, and as bactericides.

The invention is illustrated but not limited by the 01- lowing examples in which parts and percentages are by weight.

Example 1 61 parts of thiodiglycol are added slowly with stirring at l0 to l5 C. to a mixture of 23 parts of ethylene oxide and 33.5 parts of sulphur dioxide. The temperature is allowed to rise to 20-23" C. during 2 hours and maintained at this temperature for a further 4 hours. Excess ethylene oxide and sulphur dioxide are removed by heating to 3D35 C. under reduced pressure.

There is obtained .1 15 parts of a pale yellow syrup containing 87 w./w. of his (fi-hydroxyethyl) fl-sulphitoethyl sulphon'ium inner salt.

Tris (fi-hydroxyethyl)sulphoniium chloride MP. 125 C. is readily obtained by treating the inner salt with hydrochloric acid.

Example 2 55 parts of thiodiglycol are added slowly with stirring at 5 to 0 C. to a mixture of 20 parts of ethylene oxide and 20.5 parts of sulphur dioxide in parts of methyl chloroform. The mixture is stirred at 0 C. to 5 C. for 4 hours to complete reaction. The product is a suspension of his (fi-hydroxyethyl) fi sulphitoethyl sulph0- nium inner salt in methyl chloroform.

Example 3 22. parts of ethylene oxide are stirred at l:0 C. whilst 51 parts acetic anhydnide are added and 61 parts of thiodiglycol are then added to the mixture whilst main taining the temperature at 0 to -5 C. The temperature is allowed to rise to 2530 C. during 1 hour and maintained at this temperature, cooling as necessary, until reaction is complete.

The resulting product is a pale yellow syrup containing 46.8% wJw. of sulphonium salt assumed to be fl-acet0xyethyl bis(f3-hydroxyethyl)sulphonium acetate. Tris ((3- hydroxyethyl)sulphonium chloride MP. C. is readily obtained from the product by treating with hydrochloric acid and removing water and acetic acid under reduced pressure.

Example 4 14.7 parts of ethylene oxide is passed into a stirred mixture of 102 parts of acetic anhydride and 40.7 parts .of thiod-iglycol at 35-40 C. When addition is complete the mixture is stirred for a further 1 hour. The product contains approximately 40% w./w. of acetyl derivatives of trisqi-hydroxyethyl)sulphonium acetate.

Example 5 11 parts of ethylene oxide and 125 parts of methyl chloroform are stirred at 15 to -10. C. whilst 19.5 parts of acetyl chloride are slowly added. 31 parts of thiodiglycol are slowly added whilst maintaining the temperature below -10 C. and when the initial vigorous reactionis complete the temperature is allowed to rise 'ture during 1 /2 to 2 hours, maintaining the reaction mixture at -5 C. to l C. The ethylene oxide may be added as liquid, or passed in as gas. The mixture is then stirred at C. to C. fior'a further 1 hour and then the temperature is allowed to rise to 0 C. during 4 hours, and then to C. during a further 4 hours using cooling as necessary.

There is obtained 711 parts of a pale yellow syrup containing 88-90% w./w. of bis(,B-hydroxyethyl)-,8-suphitoethyl-sul phonium inner salt and 1-2'% free sulphur dioxide. 7

Example 7 40 parts sulphur trioxide are added slowly with stirring at -40 C. to a solution of 22 parts of ethylene oxide in 150 parts of carbon tetrachloride. The resulting suspension is stirred at -35 to -40 C. whilst 61 parts of thiodiglycol are slowly added. The temperature is allowed to rise to 10 C. during 1 hour and is maintained at -10 C. for a further 4 hours. Carbon tetrachloride and excess ethylene oxide are removed at 20-25 C. under reduced pressure. There is obtained 112 parts of a dark brown oily liquid containing 31% by Weightof bis(fihydroxyethyl)-fi-sulphatoethyl sulphonium inner salt.

Tris(fi-hydroxyethyl)sulphonium chloride MP. 125 C. is readily obtained by treating the inner salt with boiling water, neutralising with barium hydroxide, filtering from precipitated barium sulphate, neutralising with hydochloric acid and evaporating to low bulk.

Example 8 Example 9 25.6 parts of diallyl sulphide and 14.4 parts of sulphur dioxide are stirred at -10 C. to -15 C. and 13.0 parts of propylene oxide are slowly added. After stirring at -10 C. for a further 3 hours the mixture is allowed to warm at room temperature and all volatile starting 4 materials removed at 25 C. under reduced pressure (15 min). There is obtained 35.6 parts of a viscous yellow oil containing 94.0% of (fi-sulphitopropyl)bis-allyl sulphonium inner salt as determined by treating the product with dilute acid and determining the evolved sulphur dioxide.

Example 10 75 parts of bis(5-hydroxypropyl)sulphide are added slowly with stirring at -l0 C. to 15 C. to a mixture of 23 parts of ethylene oxide and 33.5 parts of sulphur dioxide. The temperature is allowed to rise slowlyto 0-5 C. during 2 hours, maintained at 05 C. for a further 3 hours and then allowed to rise to 20-25" C. The

product is a pale yellow syrup containing 86-88% of bis(fi-hydroxypropyl)-B sulphitoethyl sulphonium inner salt and 1-2% uncombiued sulphur dioxide.

Example 11 61 parts of thiodiglycol are added slowly at l5 to --20 C. to 33.5 parts of liquid sulphur dioxide with stirring. 23 parts of ethylene oxide are then added slowly maintaining the reaction temperature at -l0 to 5 C.

The temperature is allowed to rise slowly to 0-5 C. during 2 hours, maintained at0-5" C. for a further 3 hours and then allowed to rise to 20-25" C. There is obtained a pale yellow syrup containing 89-91% of bis(hydroxyethyl)-;8-sulphitoethylsulphonium inner salt and 12% uncombined sulphur dioxide.

Example 12 In place of the 23 parts of ethylene oxide used in Example 1 there may be used 30 parts of propylene oxide. The product is a. pale yellow syrup containing 65-70% WJW. of bis(,8-hydroxyethyl)-,B-sulphito propylsulphonium inner salt.

Example 13 In place of the 23 parts of ethylene oxide used in Example 7 there may be used 36 parts of propylene oxide. There is obtained a pale yellow syrup containing -65% of bis(B-hydroxypropyl)-fl-sulphitopropylsulphonium salt.

Example 14 in place of the 61 parts of thiodiglycol used in Example 8 there may be used 53 parts of ethyl-,B-hydroxyethylsulphide. The product-is a pale yellow syrup containing 85-90% w./w. of ethyl-,B-hydroxyethyl-B-sulphitoethylsulphonium inner salt.

Example 15 phonium chloride by treatment with hydrochloric acid and evaporation and water and acetic acid under reduced pressure.

7 Example 16 droxypnopynsulphonium chloride by treatment with hydrochloric acid and evaporation of water and acetic acid under reduced pressure.

What we claim is:

1. A process for the manufacture of an inner sulphonium salt which comprises reacting at a temperature between -50 C. and 50 C., an organic sulphide R SR with an alkylene oxide selected from the group consisting of ethylene oxide, propylene oxide and butylene oxide and an acid component selected from the group consisting of carbon dioxide, sulphur dioxide, sulphur trioxide, acetic anhydride, propionic anhydride, maleic anhydride, suc cinic anhydride, acetyl and propionyl bromides and chlorides, the substituents R and R being selected from the class consisting of alkyl, alkenyl containing from 2-3 carbon atoms, phenyl, naphthyl, and radicals of the formula CHR CHR OH where R and R are selected from the class consisting of hydrogen and alkyl containing from 1 to 3 carbon atoms.

2. Process according to claim 1 wherein the reaction is carried out at temperatures within the range of -15 C. to 5 C.

3. Process according to claim 2 wherein the reaction is carried out in the presence of an inert organic liquid diluent.

4. Process according to claim 1 wherein the organic sulphide R -S-R is thiodiglycol.

5. Process according to claim 4 wherein the acid component is sulphur dioxide.

6. Process according to claim 1 wherein the acid component is acetyl chloride.

7. Process according to claim 1 wherein the acid component is sulphur trioxide.

8. Process according to claim 1 wherein the acid component is carbon dioxide.

9. Process according to claim 1 wherein the alkylene oxide is ethylene oxide; the sulphide is thiodiglycol; and the acid component is sulphur dioxide.

10. Process according to claim 1 wherein the alkylene oxide is ethylene oxide; the sulphide is thiodiglycol; and the acid component is acetic anhydride.

11. Process according to claim 3 wherein the diluent is a solvent selected from the group consisting of methyl chloroform, tetrachlorethane, carbon tetrachloride, perchlorethylene, trichlorofiuoroethane and an excess of one of said reactants.

12. A process for the manufacture of an inner sulphonium salt which comprises reacting at a temperature between C. and 50 C., an organic sulphide of the formula R S-R with ethylene oxide and S0 the substituents R and R being selected from the class con sisting of alkyl, alkenyl containing from 2-3 carbon atoms, phenyl, naphthyl, and radicals of the formula wherein R and R are selected from the class consisting of hydrogen and alkyl containing from 1 to 3 carbon atoms.

References Cited by the Examiner UNITED STATES PATENTS 2,813,898 11/57 Gaertner 260-505 FOREIGN PATENTS 943,83 0 6/56 Germany.

CHARLES B. PARKER, Primary Examiner. 

1. A PROCESS FOR THE MANUFACTURE OF AN INNER SULPHONIUM SALT WHICH COMPRISES REACTING AT A TEMPERATURE BETWEEN -50*C. AND 50*C., AN ORGANIC SULPHIDE R3-S-R4 WITH AN ALKYLENE OXIDE SELECTED FROM THE GROUP CONSISTING OF ETHYLENE OXIDE, PROPYLENE OXIDE AND BUTYLENE OXIDE AND AN ACID COMPONENT SELECTED FROM THE GROUP CONSISTING OF CARBON DIOXIDE, SULPHUR DIOXIDE, SULPHUR TRIOXIDE, ACETIC ANHYDRIDE, PROPIONIC ANHYDRIDE, MALEIC ANHYDRIDE, SUCCINIC ANHYDRIDE, ACETYLK AN DPROPIONYL BROMIDES AND CHLORIDES, THE SUBSTITUENTS R3 AND R4 BEING SELECTED FROM THE CLASS CONSISTING OF ALKYL, ALKENYL CONTAINING FROM 2-3 CARBON ATOMS, PHENYL, NAPHTHYL, AND RADICALS OF THE FORMULA CHR1CHR2OH WHERE R1 AND R2 ARE SELECTED FROM THE CLASS CONSISTING OF HYDROGEN AND ALKYL CONTAINING FROM 1 TO 3 CARBON ATOMS. 